Impaired but reversible vascular reactivity in a rat model of microgravity / 대한마취과학회지

BACKGROUND: The hindlimb unweighting (HLU) rat model mimics cardiovascular deconditioning following microgravity or human bed rest, particularly for the development of orthostatic intolerance. We have examined vascular responses to alpha1 adrenergic and non-alpha1 adrenergic agonists in vitro. We have also explored the reversibility of the contractile abnormalities observed. METHODS: Dose-response curves were generated to phenylephrine (PE) and norepinephrine (NE) (10(-9) to 10(-4) M), U46619 (U4) (10(-10) to 10(-6) M) at one-half log order intervals in controls (n = 6), HLU (n = 6), or recovered rats (n = 6). EC(50)s and maximal responses (E(max)) were calculated by nonlinear logistic regression analysis with PRIZM software (Graphpad, Mountain View, CA). RESULTS: Simulated microgravity results in attenuated contractile responses to both alpha1 adrenergic and non-alpha1 adrenergic agonists, but the impaired contractile phenomenon reverses with time. CONCLUSIONS: The decreased vascular reactivity after microgravity and prolonged bed rest could cause attenuated baroreflex function and produce orthostatic intolerance, but that problem resolved with time.

Impaired but reversible vascular reactivity in a rat model of microgravity / 대한마취과학회지

BACKGROUND: The hindlimb unweighting (HLU) rat model mimics cardiovascular deconditioning following microgravity or human bed rest, particularly for the development of orthostatic intolerance. We have examined vascular responses to alpha1 adrenergic and non-alpha1 adrenergic agonists in vitro. We have also explored the reversibility of the contractile abnormalities observed. METHODS: Dose-response curves were generated to phenylephrine (PE) and norepinephrine (NE) (10(-9) to 10(-4) M), U46619 (U4) (10(-10) to 10(-6) M) at one-half log order intervals in controls (n = 6), HLU (n = 6), or recovered rats (n = 6). EC(50)s and maximal responses (E(max)) were calculated by nonlinear logistic regression analysis with PRIZM software (Graphpad, Mountain View, CA). RESULTS: Simulated microgravity results in attenuated contractile responses to both alpha1 adrenergic and non-alpha1 adrenergic agonists, but the impaired contractile phenomenon reverses with time. CONCLUSIONS: The decreased vascular reactivity after microgravity and prolonged bed rest could cause attenuated baroreflex function and produce orthostatic intolerance, but that problem resolved with time.

Pneumothorax after restoration of spontaneous respiration in a patient with liver segmentectomy: A case report / 대한마취과학회지

Pneumothroax may occur during and after general anesthesia unexpectedly, and the diagnosis may be difficult when the manifestations are non-specific. An early diagnosis and treatment is important to prevent tension pneumothorax. Pneumothorax can be occurred from injury to the chest wall, airway, lung, and diaphragm. We report a case of a 50-year-old female patient who underwent segmentectomy of liver under general anesthesia and developed pneumothorax after restoration of spontaneous respiration from unexpected diaphragm injury.

Respiratory failure following patient-controlled analgesia (PCA) in a patient with chronic renal failure: A case report / 대한마취과학회지

A 28-year old woman in DM (Ed note: Define DM) and chronic renal failure underwent an uneventful open reduction and internal fixation for an ankle fracture under spinal anesthesia. PCA with fentanyl and tramadol was started in the operating room with a background infusion of 2 ml/hr (10 microgram/h of fentanyl and 6 mg/h of tramadol), a bolus dose of 2 ml and a lockout interval of fifteen minutes. Approximately eight hours after initiating PCA the patient was found unresponsive in the ward with respiratory failure. Resuscitation was started with endotracheal intubation and cardiac massage with an injection of epinephrine and atropine. The patient made a full and immediate recovery two hours later.